A woman in her 40s or 50s who sexually "preys" on males under 25. This behaviour is often touted as "empowering" and "role-reversal" by feminist pundits, but probably the role "reversed" is either best described as a stereotypcal male "mid-life crisis" relationships, if not actual pedophilia, depending on the age of the "prey".

The fan outfit "Twilight moms" are a good example of this behaviour - certainly, if mobs of 40 and 50 year old men collected to scream at teenage girls, this would probably be viewed as not just unseemly, but possibly criminal behaviour by the cougar group.

A cougar is an older woman, usually in the midst of a mid-life crisis, that dates younger men to feel better about her crows feet and saggy tits. Once thought to be on the endangered species list, the cougar has bounced back from it's grim demise mainly due to today's advanced medical technology such as botox and vaginoplasty.

24 year old male: "That chick is way hot but when she laughs, she totally sounds like she smokes a carton a day"

Friend: "Yeah man, that's a cougar, can't you tell by her stretchmarks?"